Underreamer



1. w. PIPPIN.

` UNDERREAMER.

APPLICATION llLED MAR. 8| 1918- RENEWED AUG. 10, |920.

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l IIIJI) B ki A TORNEYS J. W. PIPPIN.

UNDERREAMER.

APPLICATION FILED MAR. 8. I9Is. IIENEwED AUG. I0. 1920.

1,371,978. Patented Mar. 15,1921.

.2 SHEETS-SHEET 2.

JOHN WILLIAM PIPPIN, OF OKLAHOMA, OKLAHOMA,

AssIGNoR To PIPPIN MANUFAC- TURING COMPANY, OF OKLAHOMA, OKLAHOMA.

UNDERREAMER.

Specification of Letters Patent.v

Patented Mar. 15, 1921.

Application filed March 8, 1918, Serial No. 221,195. Renewed August 10, 1920. Serial No. 402,679.

To aZZ whom it may concern:

Be it known that I, JOHN W. PIPPIN, a citizen of the United States, and a resident of Oklahoma city, in the county of Oklahoma and State of Oklahoma, have invented certan new and useful Improvements in Underreamers, of which the following is a specification.

Iy invention is an improvement in under-reamers, and has for its object to provide a device of the character specified, wherein the cutting bits are so `mounted that 'they may be held in contracted position during the insertion of the reamer through the casing by latch mechanism, which is released when the bits have `passed through the casing to permit them to expand, and wherein the bits are so mounted that they will be firmly braced and held during the cutting action against possibility of displacement.

In the drawings: I

Figure 1 is a longitudinal section of under-reamer, with the bits contracted;

Fig. 2 is a similar view, with the bits expanded;

Figs. 3 and 7 are sections on the lines 3 3 and 7 7, respectively, of Fig. 2, each view looking in the direction of the arrows adj-acent to the line;

Fig. 4 is a view of the inner side; i

Fig. 5 is a front view the bits expanded; y

Fig. 6 is a section on the line 6-6 of Fig. 5, looking in the direction of the arrows adjacent to the line;

ig. 8 is a perspective view of the lower end vof the reamer with the bits removed;

Fig. 9 is a perspective view of the lower end of the rod and head to which the bits are pivoted;

Fig. 10 is al perspective view of the locking sleeve;

IFig. 11 is a perspective view of the latch plate;

Fig. 12 is a similar pin for the same; and

Fig. 13 is an end view of the sleeve.

In ythe present embodiment ofthe invention, the body 1 of the tool is provided at its upper end with a threaded tapered stem 2 for engagement by an operating mechanism for the tool, and the body is longituthe the latch plate from of the reamer, with view of the holding dinally bored at its lower end. This recess or bore is flared at the lower end of the body and is enlarged intermediate its ends, as indicated at ently described. Between the enlargement '5 and the dared portion the bore is cylindrical, and of a size to receive the supporting rod 6 for the bits. Said rod extends through the enlargement 5, and the upper end of the rod is reduced, as shown at 7,v

while adjacent to the reduced rod isthreaded as shown at 8.

Atits lower end the rod has a cross head 9, and bits 10 are pivoted to the ends of the cross head, each bit having a transverse opening 11 for receiving the adjacent end of the cross head, and the connection between the bits and the cross head is a lost motion connection, the cross head having slots 12 for receiving pins 13 in connection with the bits. These pins, as` shown, are held in place by slides 14, which are held in guideways 15 in the outer faces' of the bits, the guideways having undercut side walls and the side edges of the slides being beveled to fit the same. lAfter the pins are inserted, the slides are placed, and-it will be noticed that the guideways taper toward their lower ends, so that the slides cannot become displaced downward. j

Each of the bits is provided with a tapering portion 16 above the pivotal connection, and this tapered portion is separated from the body of the bits by a shoulder 17, which is adapted to engage the lower end of the body l when the bits are expanded, as shown in Fig. 2.

The recess in the lower end of the body 1 is. frusto-conical and may be considered as having its outer wall inclined to act as a cam against the inclined outer faces of the portions 16 of the bits, to expand and contract vthe bits. The portions 16 of the bits are shaped to lit the opening in the lower end of the body and when thebits are expanded, as shown in Fig. 2, the portions 16 of the bits fit and fill this opening, the shoulders 17 bearing against the lower end ofthe body. j

When the bits are expanded, the pins 13 are at the outer ends of the slots 12, and when the bits are contracted the pins are at the inner ends of the slots, as shown in Fig. 1, the connection permitting the bits to move portion the 5, for a purpose to be presbodily toward the right when the portions 16 are out of the opening at the lower end of the body.v

reinforced by triangular integral webs 18 and the portions 16 of thebits are recessed on their inner faces as indicated at 23 to receive these webs. to a point such that their upper ends will be above the upper end of the opening or recess in the lower end of the body'when the bits are contracted, as shown in Fig. 1, and a sleeve 39 is held at the axis of the body between the enlarged portion 5 and the conical recess, by means of transverse pins 40, and the rod 6 passes through this sleeve. The pins 40 engage registering transverse grooves in the body and in the peripheral surface of the sleeve, thus acting to lock the sleeve from movement longitudinally of the body. The bore of the sleeve has oppositely arranged longitudinally extending grooves for receiving the extensions of the webs 18 to prevent turning of the rod with respect to the sleeve and with respect to the body. A coil spring 24 encircles the rod between the upper end of the sleeve and a stop 25 adjustable on the rod, andthe spring acts normally to force the rod upwardly and to expand the bits.` This stop is a nut which engages the threaded portion 8 of the rod and the nut is pinned to the rod as indicated at 26 to prevent displacement thereof.

A sleeve 27 is mounted loosely upon the upper reduced end 7 of the rod, and this sleeve is adapted to engage at its lower end a stop 28 on the rod, the said stop being a nut pinned to the rod. This sleeve carries a catch lug 29 at its lower end, which is adapted to coperate with a similar lug 3() on a l'latch plate 31, which is arranged within av lateral opening from the bore of the body. This plate, as will be noticed from an inspection of Figs. 1 and 2, is of considerable length, and when the bit is in the well casing, indicated at 1a, the latch plate will be held in inward position by its engagement with the casing wall. A coil spring 32 normally presses the sleeve downward, the said spring being arranged between the upper end of the bore of the recess and the sleeve, the lower end of the spring being received in a counterbore in the sleeve. The sleeve has a key-way or groove 33 at its upper end, which is adapted to b'e engaged by a projection `34 on the latch plate 31 when the sleeve is in the position vof Fig. 1, that is. when the bits are contracted. `When the parts are in the position of Fig. 2, that is, when the bits are expanded, this groove is out of register with the projection 34, and

the engagement of the lug with the pe-- ripheral surface of the sleeve prevents outward swinging of the lowerend of the plate. When the parts are in the position of Fig. 1,

The webs are extended l moving the Levante thel lug may be moved in the groove 33, so that-the outward swinging movement of the lower end of the plate to release the catches The head is braced against the rod 6 and 35 in the lower end of the cross head 9, and

the rod is drawn down, compressing the spring 24. As the rod moves downward, the portions 16 of the bits are moved out of the openings at the lower end of the body, permitting them to contract. At the same time the spring 32 causes the sleeve 27 to follow the rod, and when the catch 29 of the sleeve moves below the catch 30 of the latch plate it may be engaged beneath the said catch, thus locking the rod against upward movement. The parts may be temporarily held in this position by means of a ring 36 which is slipped over the reamer to about the center of the latch plate. rlhe reamer is lowered into the well, and the ringwill engage the top of the casing and will be pushed oli' the reamer, but the engagement of the latch plate with the casing wall will prevent disengagement of the lugs 29 and 30.

It will be noticed that a facing plate 37 is secured to the body of the reamer opposite the latch plate 30., and that the said latch plate is also provided with a facing plate 38 on its outer face. These facing plates have their ends beveled, and they are of a thickness to hold the reamer at the center of the casing. When they become worn they may be removed and replaced by other facings. When the latch plate passes below the bottom of the casing, it will be swung outward, because'of the fact that the lugs 29 and 30 have their coperating faces 'inclined or beveled, as shown. As soon as the latch lswings outward, the lugs will be released,

and the spring 24 will force the rod upward, pxortions 16 of the bits into the openings at t e lower end ofthe body and expanding the bits. At the same time the sleeve, moving upward, will hold the latch plate from outward movement, because of the fact that the projection 34 no longer registers with the groove 33. The bits are y now in position for reaming.

When it is desired to withdraw the reamer, 1t 1s drawn upward until the bits engage the :lower end of the casing. Further movement of the reamer will pull the bits downward, together with the rod 6, compressing lthe spring 24 until the bits move into the well casing, when they will be held contracted by their engagement with the casing. The lug .29, being on the sleeve 27, will not interfere with the downward movement of the rod "under the above conditions. It will be noticed upon an inspection of Fig. 10 that the catch lug 29 is of a length corresponding to ist the diameter of the sleeve and of the bore of the body. This lug moves against the inner face of the latch plate during its upward and downward movement, thus preventing rotation of the sleeve in the bore of the body.

A plate'spring 41 is secured to the inner face of the latch plate, the said spring being connected at-its` upper end just below the lug 30 and this spring is designed to swing out the lower end of the latch bar to make positive the disengagement of the catches of the latch bar and the sleeve. The

Abar is also hollowed out or recessed on its inner face and at its lower end, as indicated at 42, for thesake of lightness. A second spring 43 is'arranged at the upper end of the latch bar on the outer face thereof, and this spring has a lug 44 which extends laterally inward to the opening for receiving the pivot pin 45 that pivots the latch plate to the body. It will be noticed frolr an inspection of Fig. 12 that this pin 45 has an annular groove 46 at its center, and the lug 44 engages in this groove The spring 43 is held 1n place by fitting it in a dovetail groove in the latch bar. The projection 12 preventsdisplacement of the pin 45. The sleeve 39 not only serves as a stop for the lower end of the spring 24 and as a guide for the rod 6, but facilitates the assembling and disassembling of the reamer. The webs 18 and their extensions, in addition to serving as keys to prevent rotation of the rod with respect to the sleeve, strengthen and reinforce'the rod. Inaddition to the grooves for the web extensions, the sleeve has other longitudinal internal grooves46 for permitting the passage of sand and the like which might obtain entrance to the central bore outward.

Referring to Figs. 1 and 2, it will be seen that the opening or recess for the portions 16 of the bits is a tapering or conical recess consisting of portions of unequal taper. The lower portion, that is, from the large end of the recess inward for approximately one-third the depth of the recess, is of less taper than the remaining portion, and the portions 16 are shaped to fit and fill the two portions of the recess. This proportion of the inclined wall of the opening permits the bits to contract with a. minimum of downward movement, as will be evident from Fig. l. In addition, the bit is greatly strengthened at the shoulder 17 where breakage is very liable to occur from the use of the bit. By having the wall of less taper at this point more material can be put into the bit at the point where it is y a spring operating said sleeve in an needed. The' abovel arrangement also assists in eliminating a large part of the wedg ing action on the parts 16 of the bits between the outer face thereof and the walls of the opening.

In use, where breakage occurs in the bits, it is at the shoulder, between the shank and the body of the bit. To prevent leaving any portion of the bit in the well casing, should breakage occur, the pivotal connection of the bits with the rod is below this shoulder and, should breakage occur, the shank will be held in the socket while the bit will be held by its pivotal connection.

It will be noticed from an inspection of Figs. 5 and 8 that the under reamer body is provided near the pins 40 and between the same with a vertical groove 50 and with an opening 51 at the lower end of the groove, said opening extending into Lthe body. This opening and groove are for the purpose of permitting the removal of sand and mud that might get into the body of the reamer.

I claim:

1. The combination in a reamer, of a body portion, a bit-supporting rod, a sleeve abutting the rod and movable in one direction independently of the rod, a latch engaging said sleeve, and a Ispring for pressing the latchoutward, substantially as set forth.

2. In an apparatus substantially as described, in combination with the body and the bits mounted to expand and contract, a supporting rod for said bits, a spring operating said rod in one direction, a sleeve, opposite direction to that of the operating rod spring, a latch coperating with saidl sleeve, and a spring between the latch and the rod.

3. In an under-reamer, a body having a longitudinal bore, a rod mounted to slide in the bore, a stop on the rod, a sleeve in the bore between the rod and the body and de-l tachably connected with the body, a spring between the stop and the sleeve,4 said sleeve having longitudinally extending keyways and the rod having keys for engaging the keyways, and the sleeve tudinally extending specified.

4. In an under-reamer, a body having a longitudinal bore, a rod mounted to slide i the bore, a stop on the rod, a sleeve in the bore between the rod and the body and detachably connected with the'body, a spring between the stop and the sleeve, said sleeve having longitudinally extending keyways and the rod having keys for en aging the ke ays.

JOHN IVI LIAM PIP IN.

having other longigrooves for the purpose 

